review placement of loss of X cell terms

[sbello]

We have the term 'loss of hippocampal neurons' this is currently not a child of 'decreased hippocampus cell number' seems like it should be.
We should also check the parents of other loss of X terms

[anna-anagnostop]

Should review annotations to:

• hippocampus hypoplasia MP:0030004 (currently 3 annotations)
• hippocampal neuron degeneration MP:0000811 (with 66 annotations)
• decreased hippocampus cell density MP:0020635 (zero annotations but see Genotype MGI:5550547 annotated to 'hippocampal neuron degeneration')
• decreased hippocampus cell number MP:0020629 (zero annotations)
• loss of hippocampal neurons MP:0003240 (with 37 annotations)

[anna-anagnostop]

Other loss of X terms include:

• loss of vibrissae MP:0001280 (inability to retain vibrissae, check EQ and placement under abnormal vibrissa number MP:0009003 , see also annotations to sparse vibirissae MP:0001283)
• loss of eyelid cilia MP:0000425 (inability to retain vibrissae, check EQ and placement, see also annotations to decreased eyelid cilium number MP:0013897
• loss of GABAergic neurons MP:0003246
• loss of dopaminergic neurons MP:0003244 (also check annotations to decreased dopaminergic neuron number MP:0011448)
• loss of glutamate neurons MP:0003248 (annotations do not match EQ)
• loss of cortex neurons MP:0003241 (also check annotations to decreased cerebral cortex cell number MP:0020594)
• loss of basal ganglia neurons MP:0003242 (annotations do not match EQ)

Loss of X neuron terms are generally defined as loss "commonly due to an apoptotic event" and use absent in their EQs.